import java.util.Scanner;
/**
 * Created with IntelliJ IDEA
 * Description:
 * User: Administrator
 * Data: 2023 - 05 - 17
 * Time: 23:20
 */
//法1
/*public class Practice {
        public static void main(String[] args) {
            Scanner in = new Scanner(System.in);
            while (in.hasNextLine()) {
                String scanner = in.nextLine();
                String ret = main1(scanner);
                System.out.println(ret);
            }
        }
        public static String main1(String args){
            String string = new String("");
            for(int i = 0; i < args.length(); i++){
                char ch = args.charAt(i);
                if(!string.contains(ch + "")) {
                    string += ch;
                }
            }
            return string;
        }
}*/

//法2
import java.util.Scanner;
public class Practice {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String scanner = in.nextLine();
            String ret = main1(scanner);
            System.out.println(ret);
        }
    }
    public static String main1(String args){
        StringBuilder stringBuilt = new StringBuilder("");
        for(int i = 0; i < args.length(); i++){
            char ch = args.charAt(i);
            if(stringBuilt.indexOf(ch + "") < 0) {
                stringBuilt.append(ch);
            }
        }
        return stringBuilt.toString();
    }
}